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SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    190686, 190675, 190700, 190680, 190701, 
    190679, 190681, 190694, 190685, 190677, 
    190688, 190687, 190678, 190682, 190684, 
    190702
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00116

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "22.44"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 16,
      "rows_produced_per_join": 16,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "19.24",
        "eval_cost": "3.20",
        "prefix_cost": "22.44",
        "data_read_per_join": "109K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`webmarco`.`cscart_product_descriptions`.`product_id` in (190686,190675,190700,190680,190701,190679,190681,190694,190685,190677,190688,190687,190678,190682,190684,190702)) and (`webmarco`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id	short_description	full_description
190675		<p>Glass Cleaner 1000 ml - Trigger</p>
190677		<p>Lucidante 250 ml previous metal cleaner</p>
190678		<p>Lumino Paraffine oil 1000 ml</p>
190679		<p>Multi use descaler.</p>
190680		<p>Pure Air 500 ml Trigger - Air Condition cleaner</p>
190681		<p>Primagel plus 500 ml with pump- disinfectant gel</p>
190682		<p>Primagel plus 50 ml - disinfectant gel</p>
190684		<p>Stahlfix 200 ml Cream for cleaning & polishing stainless steel,copper,metals</p>
190685		<p>Stoffinet 400 ml Carpet,moquete foaming cleaning spray</p>
190686		<p>Vetrobel 400 ml Glass foaming cleaning spray</p>
190687		<p>General Cleaning Liquid 1000ml Pink Fresh</p>
190688		<p>General Cleaning Liquid 1000ml Lemon Fresh</p>
190694		<p>Drain Unblocker soda 100 g</p>
190700		<p>Stainless Steel,Metals,Silver Clean & Polish 550ml</p>
190701		<p>Screen Cleaner 250 ML</p>
190702		<p>Wood Furniture & Parquet 4in1 750ml - It is the most effective and quickest way to cleanse,nourish,shine and protect all types of wood to maintain it's natural glow. It contains a UV filter to protect the surfaces of the sunlight preventing discoloration.Leave a soft a druable parfum of CEDAR, with a fusion of LAVENDER and HONEY. USES: Furniture and wooden doors painted matt or gloss. Melamine surfaces enamel or paint. Parquet and laminate. INSTRUCTIONS: Spray on a dry cloth or directly onto the cleaning surface. Rub the furniture to get the brightness and the desired result. Parquet and laminate cleaning: spray 3 or 4 times the product in a bucket with 5 liters of water and scrubbing. You can also apply 3 or 4 sprays of product over a mop and pass on the surface of parquet or laminate. PRECAUTIONS; Do not apply to wood unvarnished. Do not apply to wood treated with waxes or cleaners artificially. </p>